The Calculation of H$\beta $ Color Indices for $\delta $ Scuti Variable Stars

As part of research astronomers gather and analyze information about stars' fundamental properties. One such piece of information lies in the hydrogen beta index, gathered through spectral observations. The H-$\beta $ index is commonly used to measure surface temperature of stars as well as the age of stars or clusters. As such, it is a valuable piece of information for astronomical objects. In this study we present several hundred previously unpublished or updated H- $\beta $ index values of $\delta $ Scuti variable stars. The values were calculated from a calibration using spectroscopic observations obtained at the Dominion Astrophysical Observatory of 190 $\delta $ Scuti stars north of --1\r{ } declination and brighter than 13th magnitude.